In a preferred form of the invention described in the parent applications, a superconductor is produced by the steps of combining a plurality of layers of metal sheets to form a composite structure. The sheets are preferably pure transition metals--niobium, titanium, zirconium, or vanadium, alternate sheets being formed of different transition metals. The resulting composite structure is mechanically reduced sufficiently so that each transition metal sheet is less than 1000.ANG. thick. In the course of reduction, the composite is subjected to sufficient temperatures for sufficient times such that the transition metal layers are partially reacted to form a ductile superconducting material between the transition metal layers. Approximately one half by volume of the transition metal layers remain unreacted. These unreacted layers afford efficient flux pinning within the composite when the layers are reduced to the &lt;1000.ANG. final size. In other embodiments, powders and filaments can be used instead of initial layers.